Have no fuel delivery to the injectors when I first turn the ignition switch on (fuel pump should pump for about three seconds) or trying to start (starter engaged). Read several threads but did not locate one that addresses my specific issue . . .but could have missed one. I followed the Haynes repair manual for trouble shooting (Fuel Pump, Main Relay, etc…) and replaced the fuel pump, but it did not solve the problem. Some background . . .the car has not been started in several months.

Performed the following diagnostics as follows:

1. Charged the battery
2. Turned the ignition but the car would not start. Probable cause no spark or fuel.
3. Sprayed starter fluid in the intake and the car tried to start. I know it has spark.
4. Disconnected the fuel line going from the fuel tank to filter. Turned the ignition on and no fuel. Did not hear the fuel pump engage.
5. Pulled the back seat and checked for voltage to the fuel pump. Had voltage (did not check the actual voltage).
6. Pulled the Main Relay and placed a jumper wire from the No 1 wire (battery) to the No 7 (fuel pump). About 11.2 volts present at the Main Relay No 1 wire and fuel pump engaged and pumped fuel.
7. Checked for continuity on the Main Relay per the manual and all checked okay.
8. So I check the voltage at the Main Relay. When I first turn the ignition I have 10.2 volts on the No 7 wire and fuel pump does not engage.
9. Attempt to start (starter engaged) and I have 7.5 volts on the No 7 wire.

Appears I’m not getting enough voltage to the fuel pump. What’s causing the low voltage? I suspect it’s a faulty ECU.

 

I highly doubt it is the ECU. I haven't yet heard of a faulty ECU on an Accord since I have been on this site. The techs on here also have stated before that they rarely (if ever) see a faulty ECU.
I know the main relay tested OK for continuity, but do you think it could still be faulty? It is obviously not putting out the correct voltage as you stated. Maybe a loose or damaged wire?
I am no expert, but I figured I'd throw that out there. Good luck!

 

if you shorted out the main relay and the fuel pump pumped it sounds like its the main relay.
but if the fuel pump did nothing at 11.5 volts it could also be the fuel pump... are you SURE the fuel pump was working when you shorted the relay?

 

Thanks for the response. I'm going to repalce the Main Relay Switch today and will let you know if it solves the problem.

Fuel pump did pump at 11.2 volts, but not at 10.2 volts.

 

Replacing the switch did not solve the problem. What supplies voltage to thefuel pump? Straight from the battery or through the ECU?